1. Field of the Invention
This invention relates to a process for separating deuterium oxide (D.sub.2 O) from aqueous solutions. More particularly this invention relates to a method for increasing the concentration of D.sub.2 O in the surfactant phase of a surfactant-water mixture and then separating this D.sub.2 O-rich phase from the remainder.
2. Description of the Prior Art
Several methods of isolating D.sub.2 O from water are already known. Vacuum distillation of water is a relatively simple process but has a low separation factor and is very costly. Distillation of liquid hydrogen achieves very good separation with very low process energy requirements, but has disadvantages such as the cost of the required highly pure hydrogen and the problems of working with a liquefied gas. Chemical exchange methods are less expensive but these often require the use of catalysts or toxic and corrosive chemicals and yet do not achieve a high separation. A process taught by Shay in U.S. Pat. No. 3,058,811 uses a nonionic surface active agent having a polyalkylene glycol hydrophilic group to produce a dilute solution of the surface active agent with an enriched D.sub.2 O concentration and a concentrated solution of the surface active agent in which the concentration of D.sub.2 O has been lowered.